Study will analyze the pulsatile and/or tonic basal release of renin and prorenin in normal subjects subjected to treatment with selective beta-1 adrenergic blockade and calcium channel blockade and placebo. Twenty normal subjects on a restricted sodium diet over 6 days will be studied taking each drug separately over a 3-day period. These studies will help clarify the regulatory mechanisms involved with control of both pulsatile and tonic basal patterns of renin secretion. COMPUTER ONLY.